Shots - Health Blog

8:46 am

Thu August 30, 2012

A Troubling Rise In Drug-Resistant Tuberculosis

A doctor examines chest X-rays at a tuberculosis clinic in Gugulethu, Cape Town, South Africa in late 2007. The number of TB cases that don't respond to both first- and second-line medications is rising worldwide.

Karin Schermbrucker AP

Cases of drug-resistant tuberculosis are increasing around the globe, and at a faster rate than previously thought. And if that weren't enough, TB is quickly building resistance to more and more of the drugs commonly used to fight it.

The troubling picture emerged in a study just published in The Lancet.

The study, led by Dr. Tracy Dalton from the Centers for Disease Control and Prevention, looked at the effectiveness of second-line drugs in patients who already have TB resistant to multiple drugs or infections that don't respond to the two most powerful first-line medications. The researchers found that options for treating these people are shrinking rapidly.

Public health officials had been assuming that roughly 5 percent of TB cases are resistant to the most common TB drugs. But this study notes that in Minsk, Belarus, for example, almost half the newly reported TB infections last year were resistant to the most common drugs.

Other strains of TB won't respond to even more aggressive treatments. And, as the study notes, "the global emergence of extensively drug-resistant (XDR) tuberculosis heralds the advent of widespread, virtually untreatable tuberculosis."

As Shots reported last month, TB has piggybacked onto the HIV epidemic in South Africa, spreading rapidly among people with compromised immune systems. "The TB epidemic is driven by the HIV epidemic," Dr. Eric Goemaere, with Doctors Without Borders in Cape Town, tells Shots.

Just outside an HIV/TB clinic in the township of Khayelitsha, Goemaere says the drug resistant TB problem was ignored for many years, which allowed it to get even worse. "As we speak here we are surrounded by drug-resistant TB." Goemaere says. "It's all over the place."

Initially some local health officials called for people with drug-resistant TB to be isolated, but it quickly became apparent that this approach wasn't feasible. "They started to build hospital beds to quarantine all those patients," he says. "Then they realized that they couldn't follow the pace of diagnosis with construction."

In the township of Khayelitsha alone, Doctors Without Borders is treating roughly 300 people who have multiple drug-resistant or extremely drug- resistant TB. The patients live at home and travel each day to the clinic for treatment. They're encouraged not to share enclosed, poorly-ventilated spaces with other people.

Treatment for regular tuberculosis takes months. Treatment for drug-resistant TB can take years.

Dr. Goemaere says the community-based treatment model being used in Khayelitsha is the only viable option for tackling drug-resistant TB on a large scale in places where resources are scarce.

"By treating it in a decentralized and very aggressive way, we are going to beat that epidemic," he says. "If not, we are going to lose all the gains made on TB."